I have recently been having problems with my OMTech 80w laser not cutting fully through 3mm MDF. When cutting a square, a single side has a really clean cut and then the other 3 sides are either ‘tacked’ together with what I assume are glue spots, or the entire side just hasn’t cut through. Currently, I’m at 10mm/s and 50% min/max. When I got the machine I was cruising through MDF at 20mm/s 40% max.
I’m able to cut 3mm plywood with these settings perfectly fine, even too fine I think as the edges are always charred. What really boggles me is that there’s an xtool s1 40w in the house that uses the same MDF and it doesn’t experience these issues. (Is diode better with glue spots than co2?)
I’ve had issues with exhaust to a point that the back air assist filter thing was clogged totally. I cleaned it, and I cleaned mirror 2 & 3 and the nozzle. It helped, but not enough. I’ve heard that you can take the nozzle apart and there’s a mirror/lens in there. Should I attempt to clean that?
The plywood cutting but the MDF not is what’s stumping me. I don’t know where to begin, I want to say the MDF I’m buying is bad but I really don’t think that is the issue considering that some cuts are clean and others are half cut or barely cut.
You should decide on the following things. Is your CO2 tube ok? Are your optics ok? Is your focus ok?
Proceed in the order mentioned above with troubleshooting. Search (here in the forum) for example what a flawless M1 image looks like and see if it matches your result. If the CO2 tube is ok, you must clean everything that belongs to the “optical line”, all mirrors and the lens. Are the mirrors burnt, i.e. have deep marks that cannot be removed with isoprohanyl (technical alcohol), they must be replaced.
After this step, check and adjust your focus and make sure the laser beam is coming out of the nozzle perpendicularly.
If these 3 basic elements are in order, you also have a functioning laser machine
If there’s that much crud floating around, then all three mirrors and the lens are badly in need of thorough cleaning.
The crud can be baked onto the mirrors and the lens may be damaged from the heat, so inspect them carefully: if you see any imperfections, the laser beam will not pass through correctly.
Remember to put the lens in with the convex side upward.
Upload close-up pictures so we can look over your shoulder …
So I feel a bit silly. I cleaned the machine almost entirely and it seems to be functioning as normal. The convex piece of glass in the lens, as ednisley said, was in dire need of a clean. I did a test circle after cleaning and I was able to smoothly cut MDF 3mm against with 20mm/s at 45% power.
I have added some pictures of my laser tube(Could only upload 4), in a hope that I could get some advice on whether or not I should replace it due to the conditions it has been through(totally my vault and I am purchasing the relevant ventilation stuff to resolve this issue this week).
Although the label day says May 21 2023, we had only briefly used the machine a few times before leaving it in the garage for 6-7 months and only recently has it been really used as a work horse.
If you haven’t run your laser without cooling it should be ok. It looks a bit cloudy, but it is difficult to tell whether it is external or the coolant itself. Clean the tube and change the water and try to drive as you are used to.
If the tube is that dirty on the outside, its exit mirror is also in dire need of cleaning. Depending on how close Mirror 1 sits to the tube exit, you may need to remove Mirror 1 entirely. This shows the exit end of the tube in my machine snugged up against Mirror 1:
You’ll need cotton balls (not swabs on sticks) to get in there, an inspection mirror to see what you’re doing, and isopropyl alcohol. Test the alcohol on the outside of the tube to verify it will dissolve the crud, then gently clean the tube mirror. Roll a ball into a cylinder, wet with alcohol, get some crud out, iterate.
The antireflection coating on the outer surface won’t dissolve, but it’s entirely too easy to scratch. Use plenty of balls to avoid re-depositing crud; stop after you don’t see any crud on three successive balls.
